Many people today are involved in a sport or some other type of physical activity. Some of these activities involve a low risk chance of injury, such as walking and swimming, while others involve a high risk chance of injury, such as football and skiing.
Damaged ligaments, cartilage and tendons in joints are not an uncommon occurrence, particularly in some of these high risk activities and sports. One of the joints which requires particular skill and presents particular difficulties in repairing is the knee joint.
Numerous improvements in repairing damage to knee joints have been made over the years, and some of the major advances involve the use of endoscopic techniques and arthroscopic procedures. Arthroscopic surgery is particularly useful in excising or repairing damaged knee cartilage.
Endoscopic techniques have also been developed for use in repair and reconstruction of damaged anterior cruciate ligaments (ACL) and posterior cruciate ligaments (PCL). When the ACL in particular has ruptured and is non-repairable, it is usually replaced in young adults and the knee reconstructed through use of grafts (biological or synthetic).
In one surgical technique a single bundle reconstruction is performed to replace a torn ACL. In such a technique, a single tibial tunnel is prepared in the tibia and a single complementary femoral tunnel is prepared in the femur. In one example, U.S. Pat. No. 6,254,605 to Howell discloses methods and instruments for preparing the tibial and femoral tunnels.
In another surgical technique a dual bundle reconstruction is performed to replace a torn ACL. In a dual bundle technique, a first bundle is implanted anteromedially on the tibial site. This bundle is referred to as an anterior medial (AM) bundle. A second bundle is implanted posterolaterally on the tibial site. This bundle is referred to as a posterior lateral (PL) bundle.
To accommodate both bundles, an AM tunnel and a PL tunnel are prepared in the femur. Correct placement of the AM and PL tunnels is vital to a successful dual bundle ACL reconstruction. Incorrect tunnel placement may be a cause of failure in an ACL reconstruction. In some cases of dual bundle reconstruction however, it is difficult to accurately position one tunnel relative to the other tunnel.